1) When the mammalian brain compares the actual temperature of the body to the preferred temperature of the body, which general component is being used?
A) sensor
B) effector
C) integrator
C
2) A behavioral physiologist is studying the homeostatic control of blood pH. In a trial, a lizard runs on a treadmill for a set amount of time and the blood pH is measured. The blood pH drops as carbon dioxide is released into the bloodstream. Which component of the homeostatic feedback system is responsible for deciding if the blood pH is far enough from normal that a response is necessary?
A) effector
B) sensor
C) integrator
D) assimilator
C
3) The eleven pairs of appendages projecting from the rostral area of star-nosed moles are _____.
A) chemosensory structures
B) tactile structures
C) olfactory structures
D) gustatory structures
B
4) The correct sequence of sensory processing is _____.
A) sensory adaptation → stimulus reception → sensory transduction → sensory perception
B) stimulus reception → sensory transduction → sensory perception → sensory adaptation
C) sensory perception → stimulus reception → sensory transduction → sensory adaptation
D) stimulus reception → sensory perception → sensory adaptation → sensory transduction
B
5) Artificial electrical stimulation of a human's capsaicin-sensitive neurons would likely produce the sensation of _____.
A) cold temperature
B) hot temperature
C) tactile stimulus
D) deep pressure
B
6) Artificial electrical stimulation of a human's menthol-sensitive neurons would likely produce the sensation of _____.
A) cold temperature
B) hot temperature
C) odor of pepper
D) deep pressure
A
7) Stimuli alter the activity of excitable sensory cells and generate action potentials via _____.
A) integration
B) transmission
C) transduction
D) amplification
C
8) Immediately after putting on a shirt, your skin might feel itchy. However, this perception soon fades due to _____.
A) sensory adaptation
B) accommodation
C) reduced motor unit recruitment
D) reduced receptor amplification
A
9) A given photon of light may trigger an action potential with thousands of times more energy because the signal strength is amplified by _____.
A) the receptor
B) a G protein
C) a signal transduction pathway
D) triggering several receptors at once
C
10) Although some sharks close their eyes just before they bite, their bites are on target. Researchers have noted that sharks often misdirect their bites at metal objects and that they can find batteries buried under sand. This evidence suggests that sharks keep track of their prey during the split second before they bite in the same way that a _____.
A) rattlesnake finds a mouse in its burrow
B) male silkworm moth locates a mate
C) bat finds moths in the dark
D) platypus locates its prey in a muddy river
D
11) Which type of receptor would you expect to be most abundant in the antennae of a moth?
A) thermoreceptors
B) mechanoreceptors
C) chemoreceptors
D) electroreceptors
C
12) The middle ear converts _____.
A) air pressure waves to fluid pressure waves
B) fluid pressure waves to air pressure waves
C) air pressure waves to nerve impulses
D) fluid pressure waves to nerve impulses
A
13) Statocysts contain cells that are _____.
A) mechanoreceptors used to detect orientation relative to gravity
B) chemoreceptors used in selecting migration routes
C) photoreceptors used in setting biological rhythms
D) thermoreceptors used in prey detection
A
14) During an auditory transduction, ion flow varies across the _____.
A) tectorial membrane
B) round-window membrane
C) hair cell membrane
D) basilar membrane
C
15) Dizziness is a perceived sensation that can occur when _____.
A) the hair cells in the cochlea move more than their normal limits
B) moving fluid in the semicircular canals encounters a stationary cupula
C) rods and cones provide information that does not correspond with information received by cochlear hair cells
D) the basilar membrane makes physical contact with the tectorial membrane
B
16) The structure diagrammed in the figure is the _____.
A) neuromast
B) statocyst
C) ommatidium
D) olfactory bulb
B
17) A person able to hear only high-frequency sounds would probably have which of the following structural problems in the ear?
A) The tympanum is damaged because of chronic ear infections.
B) The basilar membrane is stiffened along its entire length.
C) The ear ossicles are abnormally thickened.
D) All of these problems could result in inability to detect low-frequency sound.
B
18) Partial or complete loss of hearing (deafness) can be caused by damage to the _____.
I) axons of the neurons associated with each hair cell that carry information to the brain
II) hair cells (the sensory receptors) in the cochlea
III) tympanic membrane, or eardrum
A) only II
B) only III
C) only I and II
D) I, II, and III
D
19) The cochlea _____.
I) amplifies sound vibrations
II) collects sound pressure waves
III) detects the frequency of sounds
A) only I
B) only II
C) only III
D) only II and III
D
20) Elephants hear sounds that are too low for humans to hear. This sensitivity is primarily due to the differences in the _____.
A) arrangement and shape of the ossicles
B) flexibility of the basilar membrane in the cochlea
C) size and flexibility of the tympanic membrane (eardrum)
D) size and shape of the outer ear
B
21) Hair cells in the vertebrate ear are responsible for transducing sound pressure waves. Ion channels in the hair cell membrane open when _____.
A) a chemical ligand binds to the ion channel
B) light is absorbed by a molecule in the membrane
C) the cell membrane reaches a threshold voltage
D) the membrane is distorted mechanically
D
22) If you experimentally reduce the concentration of K+ in the extracellular fluid surrounding hair cells in the inner ear, the result would be like which of the following?
- A) decreasing the volume of sound reaching the hair cells
- B) increasing the volume of sound reaching the hair cells
- C) decreasing the frequency of sound reaching the hair cells
- D) increasing the frequency of sound reaching the hair cells
A
23) It can be very difficult to select an angle for sneaking up to a grasshopper to catch it because grasshoppers have _____.
A) excellent hearing for detecting predators
B) compound eyes with multiple ommatidia
C) eyes with multiple fovea
D) a camera-like eye with multiple fovea
B
24) Compared to viewing a distant object, a human viewing an object held within five centimeters of the eye requires a lens that _____.
A) has been flattened, as a result of contraction of the ciliary muscles
B) has been made more spherical, as a result of contraction of the ciliary muscles
C) has been flattened, as a result of relaxation of the ciliary muscles
D) has been made more spherical, as a result of relaxation of the ciliary muscles
B
25) Sensory transduction of light in the vertebrate retina is accomplished by _____.
A) ganglion cells
B) amacrine cells
C) bipolar cells
D) rods and cones
D
26) Lateral inhibition via amacrine cells in the mammalian retina _____.
A) underlies habituation of vision
B) enhances visual contrast
C) prevents bleaching in bright light
D) recycles neurotransmitter molecules
B
27) The blind spot in the human retina is the location that has the collected axons of _____.
A) ganglion cells
B) bipolar cells
C) primary visual cortex
D) lateral geniculate nuclei
A
28) Corneal surgery is now routinely performed to change the shape of the cornea and improve vision. This surgery is beneficial because it _____.
A) improves the circulation of nutrients to the eye
B) improves the focusing of light onto the retina
C) decreases the amount of light entering the eye
D) increases the sensitivity of the photoreceptors
B
29) Rods exposed to light will _____.
A) depolarize due to the opening of sodium channels
B) hyperpolarize due to the closing of sodium channels
C) depolarize due to the opening of potassium channels
D) hyperpolarize due to the closing of potassium channels
B
30) What structures would neurobiologists look for if they are interested in determining if an animal can see in color?
A) opsins
B) electroreceptors
C) pupil
D) lens
A
31) How could you genetically modify an animal so that it would distinguish more shades of green?
A) Induce genes to produce a greater number of cone cells in the fovea.
B) Introduce genes for different opsins that respond in the green region of the spectrum.
C) Introduce genes to produce green fluid in the eyeball, because green fluids will not absorb green light.
D) Induce increased production of cGMP to increase opening of cGMP-gated sodium channels.
B
32) Which sensory distinction is NOT encoded by a difference in neuron identity?
A) red and green
B) loud and faint
C) salty and sweet
D) spicy and cool
B
33) Tastes and smells are distinct kinds of environmental information in that _____.
A) neural projections from taste receptors reach different parts of the brain than the neural projections from olfactory receptors
B) the single area of the cerebral cortex that receives smell and taste signals can distinguish tastes and smells by the pattern of action potentials received
C) tastant molecules are airborne, whereas odorant molecules are dissolved in fluids
D) distinguishing tastant molecules requires learning, whereas smell discrimination is an innate process
A
34) Most of the chemosensory neurons arising in the nasal cavity have axonal projections that terminate in the _____.
A) gustatory complex
B) olfactory bulb
C) occipital lobe
D) posterior pituitary gland
B
35) Umami perception would be stimulated by _____.
A) chocolate milk
B) a slice of roast beef
C) acidic orange juice
D) salt water
B
36) The olfactory bulbs are located in the _____.
A) nasal cavity
B) anterior pituitary gland
C) brain
D) brainstem
C
37) Which of the following sensory receptors is correctly paired with its category?
A) hair cell — mechanoreceptor
B) muscle spindle — electromagnetic receptor
C) taste receptor — mechanoreceptor
D) rod — chemoreceptor
A
38) The umami receptor in the sense of taste detects _____.
A) glucose
B) potassium ions
C) hydrogen ions
D) monosodium glutamate
D
39) Experiments with genetically altered mice showed that the mice would consume abnormally high amounts of bitter-tasting compounds in water after their _____.
A) hormone receptors for digestive hormones were reduced or eliminated, showing that bitter tastes are reinforced by digestive responses
B) salt-taste cells were altered to express receptors for bitter tastants, suggesting that animals have unregulated salt appetites
C) visual sense was reduced or eliminated, suggesting that mice learn visual cues about bitter tastes
D) sweet-taste cells were altered to express receptors for bitter tastants, suggesting that the sensation of taste depends only on which taste cell is stimulated
D
40) Two students studying physiology taste a known "bitter" substance, and both report sensing bitterness. They then sample another substance. Student A reports sensing both a bitter taste and a salty taste, but student B reports only a salty taste. What is the most logical explanation?
A) Student A had an allergic reaction to the food, causing him to perceive the food as being bitter.
B) Student A has normal "bitter" taste buds; student B has defective "bitter" taste buds that result in lower sensitivity to bitterness.
C) Student A has a protein receptor capable of detecting a bitter molecule found in that substance, whereas student B lacks that particular protein receptor.
D) Student A has normal saliva, whereas student B's saliva is more alkaline than normal.
C
41) Which of the following are present in high densities in both smooth and skeletal muscle cells?
I) cilia
II) mitochondria
III) nuclei
IV) endoplasmic reticulum
A) only I and II
B) only II and IV
C) only III and IV
D) only I, II, and III
B
42) The contraction of skeletal muscles is based on _____.
A) myosin filaments coiling up to become shorter
B) actin and myosin filaments both coiling up to become shorter
C) actin cross-bridges binding to myosin and transitioning from a high-energy to a low-energy state
D) myosin cross-bridges binding to actin and transitioning from a high-energy to a low-energy state
D
43) Compared to oxidative skeletal muscle fibers, those classified as glycolytic typically have _____.
A) a higher concentration of myoglobin
B) a higher density of mitochondria
C) a smaller diameter
D) less resistance to fatigue
D
44) Myasthenia gravis is a form of muscle paralysis in which _____.
A) motor neurons lose their myelination and the ability to rapidly fire action potentials
B) acetylcholine receptors are destroyed by an overactive immune system
C) ATP production becomes uncoupled from mitochondrial electron transport
D) troponin molecules become unable to bind calcium ions
B
45) A skeletal muscle deprived of adequate ATP supplies will _____.
A) immediately relax
B) enter a state where actin and myosin are unable to separate
C) fire many more action potentials than usual and enter a state of "rigor"
D) sequester all free calcium ions into the sarcoplasmic reticulum
B
46) Most of the ATP supplies for a skeletal muscle undergoing one hour of sustained exercise come from _____.
A) creatine phosphate
B) glycolysis
C) substrate phosphorylation
D) oxidative phosphorylation
D
47) The "motor unit" in vertebrate skeletal muscle refers to _____.
A) one actin binding site and its myosin partner
B) one sarcomere and all of its actin and myosin filaments
C) one myofibril and all of its sarcomeres
D) one motor neuron and all of the muscle fibers on which it has synapses
D
48) The muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of _____.
A) ATP needed to break actin-myosin bonds
B) calcium ions needed to bind to troponin
C) oxygen supplies needed for myoglobin
D) sodium ions needed to fire action potentials
A
49) Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?
1) Tropomyosin shifts and unblocks the cross-bridge binding sites.
2) Calcium is released and binds to the troponin complex.
3) Transverse tubules depolarize the sarcoplasmic reticulum.
4) The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.
5) An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane.
A) 1 → 2 → 3 → 4 → 5
B) 2 → 1 → 3 → 5 → 4
C) 2 → 3 → 4 → 1 → 5
D) 5 → 3 → 2 → 1 → 4
D
50) Action potentials in the heart move from one contractile cell to the next via _____.
A) chemical synapses using acetylcholine
B) chemical synapses using norepinephrine
C) electrical synapses using gap junctions
D) non-myelinated motor neurons
C
51) What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?
A) Action potentials would be continuously generated, causing convulsive muscle contractions.
B) Muscle contractions would be prevented, causing paralysis.
C) Muscle contractions could still occur, but relaxation of the muscle would be impaired.
D) Action potentials would be continuously generated, causing convulsive muscle contractions; muscle contractions would then be prevented, causing paralysis.
B
52) When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ), a series of events occurs that leads to muscle contraction. Which of the following events will occur last (that is, after all of the others)?
A) acetylcholine (ACh) release
B) conformational change in troponin
C) depolarization of the muscle cell
D) release of Ca2+from the sarcoplasmic reticulum
B
53) A patient is hospitalized with muscle spasms caused by failure of back muscles to relax after contraction. Which of the following would be most likely to help?
A) Inject calcium into the muscle cell, because it is not being released from the sarcoplasmic reticulum.
B) Induce tropomycin and troponin to bind to the myosin binding sites on actin.
C) Increase the amount of acetylcholine at the synapses between motor neurons and muscle cells.
D) Depolarize the motor neurons to send an action potential to the muscle cells.
B
"Marine cone snails from the genus Conus are estimated to consist of up to 700 species. These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms, other molluscs, or in some cases fish as their primary food sources. … conotoxins from Australian species of Conus … have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B. G. Livett, K. R. Gayler, and Z. Khalil. 2004. Drugs from the sea: Conopeptides as potential therapeutics. Current Medicinal Chemistry 11:1715-23.)
54) Refer to the paragraph above on the venom of marine core snails. This particular conotoxin inhibits acetylcholine receptors that are located _____.
A) along the motor neuron axon
B) on motor neuron dendrites
C) on the presynaptic membrane of the neuromuscular junction
D) on the postsynaptic membrane, on the muscle cell
B
"Marine cone snails from the genus Conus are estimated to consist of up to 700 species. These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms, other molluscs, or in some cases fish as their primary food sources. … conotoxins from Australian species of Conus … have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B. G. Livett, K. R. Gayler, and Z. Khalil. 2004. Drugs from the sea: Conopeptides as potential therapeutics. Current Medicinal Chemistry 11:1715-23.)
55) Refer to the paragraph above on the venom of marine core snails. What is the adaptive value of this toxin?
I) It would cause muscle spasms in the prey.
II) It would result in paralysis of the skeletal muscle of the prey.
III) It would stimulate digestive tract smooth muscle to cause nausea and vomiting of the prey.
A) only I
B) only II
C) only III
D) only I and II
B
56) An endoskeleton is the primary body support for the _____.
A) annelids, including earthworms
B) insects, including beetles
C) cartilaginous fishes, including sharks
D) bivalves, including clams
C
57) A ball-and-socket joint connects _____.
A) the radius to the ulna
B) the radius to the humerus
C) the ulna to the humerus
D) the humerus to the scapula
D
58) Among these choices, the most energetically efficient locomotion per unit mass is likely _____.
A) running by a 50-gram rodent
B) running by a 40-kilogram ungulate
C) flying by a 100-gram bird
D) swimming by a 100-kilogram tuna (bony fish)
D
59) The hydrostatic skeleton of the earthworm allows it to move around in its environment by _____.
A) walking on its limbs
B) swimming with its setae
C) using peristaltic contractions of its circular and longitudinal muscles
D) alternating contractions and relaxations of its flagella
C
60) Chitin is a major component of the _____.
A) skeleton of mammals
B) hydrostatic skeletons of earthworms
C) exoskeleton of insects
D) body hairs of mammals
C